To be sure, there’s a lot of entertainment and fun to be had from watching the Franken-free show — the senator from Minnesota was hardly a key element. The funniest stuff is from two sources and three people: Martin Short, Steve Martin, and Bill Murray. Near the beginning of the 90-minute special, Martin and Short perform together. (They’ve been taking their duo act on the road in recent years.) They are wonderfully daffy and disrespectful toward Letterman. Short’s idea of saluting Dave is to say, “Not many can say they were the number-one late-night host for two years in the early 90s.”

Toward the end of the special, Murray — who won the Mark Twin prize the previous year — appears in a foppish garb of an Elizabethan king. He wants us to believe that he’s been living out a royal existence since snagging the Twain Prize. Poker-faced and extravagantly fatuous, Murray slays the Washington, D.C., audience.

The celebrities also introduce some of Letterman’s greatest-hits clips, like one of the first “Stupid Pet Tricks” and Dave’s time spent as a Taco Bell drive-through employee.

I was very glad to be reminded of a more obscure clip shown here: Letterman’s mock-After-School Special from 1983. It’s an altogether unique little piece of filmmaking, made during a period when Letterman was open to all sorts of quirky ideas.

Franken’s comments were originally inserted toward the end of the special, with the senator also introducing a clip of the Late Show monkey-cam. In a statement, PBS said it decided that “the inclusion of Sen. Franken in the broadcast at this time would distract from the show’s purpose as a celebration of American humor,” although I think anyone looking at the special could have soldiered through the “distraction” without any ill effects. I am assuming that — in keeping with PBS’s concern for our well-being — Letterman’s own comment late in his closing speech that Franken himself deserves the Twain Prize, will also be edited out. Letterman’s acceptance speech is humble, chatty, and only mildly funny — he’s clearly operating in full-retirement mode these days. No matter: the people assembled to salute him bring the laughs.